Biomedical subjects

A M Carossino

Publications and source records attributed to A M Carossino.

9 recordsLinked to original sources

PubMed1997

Type 2 helper T-cell predominance and high CD30 expression in systemic sclerosis.

The pattern of cytokine production of skin-infiltrating T cells from patients with progressive systemic sclerosis was investigated. Most CD4+ T-cell clones generated from skin biopsy specimens showed a type 2 helper (Th2) cytokine profile (production of interleukin-4, but no interferon (IFN)-gamma). High interleukin-4 but little or no IFN-gamma mRNA expression was found by in situ hybridization in skin perivascular mononuclear cell infiltrates. The immunohistochemical analysis revealed CD30 expression by high numbers of CD4+ T cells in the same specimens. Finally, the great majority of patients with diffuse disease had elevated levels of soluble CD30 in their sera. These data suggest the existence in patients with progressive systemic sclerosis of a predominant activation of Th2-like T cells, which may account for the major alterations (endothelial cell injury, fibrosis, and autoantibody production) occurring in this disease.

Adult↗

PubMed1996

CD40 expression and function in murine B cell ontogeny.

The CD40 antigen, a member of the nerve growth factor/tumor necrosis factor receptor family, is expressed on all mature B lymphocytes and plays a crucial role in B cell activation, T cell-dependent antigen-driven isotype switching and germinal center formation. We have analyzed CD40 expression and function during mouse B cell development by examining B cell precursors in normal mice and in transgenic animals in which B cell development is frozen at discrete stages. These models included RAG-2-/- mice, and transgenic littermates that express a mu heavy chain and/or the bcl-2 proto-oncogene transgene. CD40 was undetectable at the pro-B cell stage, but was expressed, although at low levels, on pre-B cells. However, pre-B cells failed to respond to CD40 triggering either by expression of CD23 or by proliferation in the presence of IL-4. Overexpression of bcl-2 increased the density of CD40 expression on pre-B cells: these cells respond to CD40 ligation by expressing CD23 and by proliferating in the presence of IL-4.

Animals↗

PubMed1996

c-myb proto-oncogene is expressed by quiescent scleroderma fibroblasts and, unlike B-myb gene, does not correlate with proliferation.

Systemic sclerosis (scleroderma) is characterized by excessive deposition of extracellular matrix constituents. Although it has been proposed that tissue fibrosis is due to increased fibroblast synthesis of various collagen polypeptides, there is some experimental evidence that patients with systemic sclerosis have a defect in the control of fibroblast growth. The myb family of genes includes, among others, the c-myb proto-oncogene and the structurally related gene, B-myb, which are both implicated in the regulation of differentiation and/or proliferation of hematopoietic and nonhematopoietic cells. To elucidate the molecular basis responsible for scleroderma fibroblast proliferation, we therefore elected to investigate the expression of c-myb and B-myb genes in scleroderma and control cells. Using the reverse transcriptase polymerase chain reaction technique, we detected c-myb transcripts in scleroderma skin fibroblasts rendered quiescent by serum deprivation. Under the same experimental conditions, c-myb message was not found in normal skin fibroblasts, but, after serum stimulation, c-myb RNA was clearly evident from 3 to 72 h in both normal and pathologic cells. Treatment of these cells with c-myb antisense oligonucleotides caused downregulation of c-myb expression, and the inhibition of scleroderma fibroblast proliferation was 42%, whereas in normal fibroblasts the inhibition was weaker (22%). In contrast to c-myb, in normal and scleroderma fibroblasts the level of expression of B-myb correlated with cell proliferation assessed by cell count, and densitometric analysis showed that B-myb message was 1.5-5 times higher in most of pathologic cells studied. The antisense B-myb oligonucleotides had a weaker antiproliferative effect compared with antisense c-myb, inhibiting scleroderma and normal fibroblasts by 23% and 13%, respectively. These data suggest that the B-myb and c-myb genes may play a role in scleroderma fibroblast proliferation and function.

Aged↗

PubMed1989

Biologic and clinical significance of cytokine production in B-cell malignancies.

Cytokines are a group of polypeptide hormones endowed with pleiotropic biological properties. Normal B lymphocytes produce a number of these factors that subserve important regulatory functions in the combined processes of proliferation and differentiation. Also neoplastic B cells can release cytokines and, simultaneously, respond to the same factors in an autocrine circuit that supports their malignant growth. In addition, tumor cells can make use of the factors released by normal cells, either spontaneously or under the influence of inductive signals from the neoplastic cells. Inappropriate or excessive release of cytokines may have an important role in the pathophysiology of some clinical features. Thus, neutralization of cytokine biologic activity in vivo could be a therapeutic strategy for treatment of human B-cell neoplasias.

B-Lymphocytes↗

PubMed1988

Potential role of interleukin-1 as the trigger for diffuse intravascular coagulation in acute nonlymphoblastic leukemia.

Abnormalities of coagulation are common in patients with acute nonlymphoblastic leukemia, although the mechanisms involved are unclear, except in a few cases. To investigate the pathogenesis of this coagulopathy, suspensions of purified leukemic cells were prepared and tested for procoagulant activity. Neither the leukemic cells nor their supernatants directly accelerated the clotting of plasma. Since the leukemic cells did not possess direct procoagulant activity, their ability or inability to elaborate a mediator of cellular coagulant properties, interleukin-1, was studied. Leukemic cells from patients with coagulopathy elaborated interleukin-1, and addition of phytohemagglutinin increased interleukin-1 release. In contrast, no interleukin-1 was released, before or after stimulation with phytohemagglutinin, from leukemic cells from patients without coagulopathy. Leukemic cells from another group of patients with abnormalities of coagulation released interleukin-1 only after phytohemagglutinin treatment. In terms of the coagulation mechanism, interleukin-1 containing supernatants from leukemic cell cultures induced the procoagulant receptor tissue factor, a co-factor in the initiation of coagulation, on the endothelial cell surface. There was coordinate suppression of the anticoagulant endothelial cell receptor thrombomodulin, a co-factor for the antithrombotic protein C pathway. Antibody to interleukin-1 prevented these changes in cellular coagulant properties. Taken together, these changes result in a shift in the balance of endothelial cell coagulant properties to an activated state in which mechanisms promoting procoagulant reactions on the vessel surface predominate. Synthesis and release of the mediator interleukin-1 by leukemic cells thus defines a new mechanism through which malignant cells can potentially activate the coagulation mechanism.

Acute Disease↗

PubMed1987

Characterization of cells from invaded lymph nodes in patients with solid tumors. Lymphokine requirement for tumor-specific lymphoproliferative response.

The specific immune response against the malignant cells was investigated in patients with urinary bladder or larynx cancer. Lymphocytes from lymph nodes that drain the tumor site were tested for their proliferative and cytotoxic capacities against autologous malignant cells isolated from the primary tumor. In no occasion was a proliferative or a cytotoxic response observed. However, when the lymph node cell suspensions were depleted of cells expressing both OKM1 and Leu-7 markers by rosetting with the appropriate mAbs, a proliferative response could be observed. The lymphocytes responded to autologous tumor cells only if IL-2 was added to the cultures. IL-2 alone induced some cell proliferation, which was not, however, comparable to that observed in response to both IL-2 and tumor cells. A panel of allogeneic tumor cells consistently failed to stimulate OKM1-, Leu-7- cells in vitro. Response to autologous tumor cells was not caused by HLA-encoded molecules, as occurs in the autologous mixed lymphocyte reaction, since OKM1-, Leu-7- cells failed to be stimulated by autologous non-T cells. A proliferative response was observed only with cells from lymph nodes that had been classified as invaded by malignant cells according to histopathologic criteria. Cells from noninvaded lymph nodes consistently failed to respond. Cells stimulated with autologous tumor cells could be expanded in short-term lines by continuous addition of IL-2 and malignant cells. One of these lines, which comprised mainly T8+ cells, was stimulated to proliferate only by autologous tumor cells, and its proliferative response was inhibitable by anti-class I and not by anti-class II mAbs. This line showed lytic capacities against autologous malignant targets, while it was inefficient against all of the other allogeneic cells tested. In another set of experiments, the mechanisms whereby exogenous IL-2 had to be added to the cultures to sustain a proliferative response against neoplastic cells were investigated. When cocultured with autologous malignant cells, OKM1-, Leu-7- lymphocytes expressed IL-2 receptors, as could be assessed by anti-Tac fluorescent staining. Under these culture conditions, these cells did not produce IL-2, and no proliferation was observed. Addition of purified IL-1 to the cultures induced IL-2 production and cell proliferation. It is concluded that metastatic lymph nodes contain a T cell population that can be detected in a proliferative assay when both suppressor cells are removed and the appropriate molecular signals are supplied.

Antigens, Surface↗

PubMed1986

Presence of activated T-cells with a T8+ M1+ Leu 7+ surface phenotype in invaded lymph nodes from patients with solid tumors.

The lymphocyte surface phenotype of lymph nodes from patients with larynx or urinary bladder carcinoma was investigated by using a panel of monoclonal antibodies. The phenotype pattern of lymphocytes from lymph nodes invaded by malignant cells (as assessed by histopathology) was different from that of the cells from noninvaded or normal control nodes. Although the proportion of natural killer cells or macrophages was similar in the 3 groups of lymph nodes, invaded lymph nodes contained a higher proportion of T-cells and a lower B-cell percentage. Furthermore, cells from invaded nodes comprised 15-20% of T3+ T8+ cells that coexpressed the M1 marker and, to some extent, also the Leu 7 marker. A large proportion of cells with multiple markers were activated, as shown by the expression of Tac and HLA-DR antigens. In 2 patients activated T8+ cells expressing also M1 and Leu 7 markers infiltrated the tumor site. The presence of these activated cells both in involved nodes and tumor mass may indicate that they originate in response to cancer.

Antigens, Differentiation, T-Lymphocyte↗

PubMedDate not supplied

[Patterns of ventricular late potentials in systemic sclerosis: a noninvasive method in the study of cardiac involvement].

The aim of our study was to ascertain the prevalence of ventricular late potentials (VLP) in systemic sclerosis (SSc) and their correlation with the immunologic patterns and cutaneous and pulmonary involvement of the disease. Ventricular late potentials, which are low-amplitude high-frequency signals present in the terminal portion of the QRS complex, express the delayed and fragmented depolarization of ventricular myocardial fibers. Observed in myocardial interstitial fibrosis, they are characteristic of the myocardial alterations occurring in SSc. Twenty-six patients with SSc (1 man, 25 women) with a confirmed lack of cardiac involvement (negative history and normal clinical, electrocardiographic, and echocardiographic findings) underwent signal averaged high resolution electrocardiography. Pulmonary involvement was evaluated by pulmonary function tests and high resolution computed tomography. The degree of cutaneous involvement was assessed by skin score. In the patients with SSc, VLP presence with time-domain analysis was 30.8% when a 25-250 Hz pass-band filter was used and 26.9% when a 40-250 Hz pass-band filter was used whereas with frequency domain analysis it was 23.1%. Ventricular late potentials were confirmed in 7.7% of the control subjects, no matter what filter or technique was used. No significant correlations among VLP, pulmonary involvement, skin score and specific antibody patterns were found. Although this technique requires further consolidation, it seems to have the potential for use as an early index of myocardial fibrosis.

Adult↗

PubMedDate not supplied

Effect of melatonin on normal and sclerodermic skin fibroblast proliferation.

OBJECTIVE: We studied the effect of melatonin (MLT) (N-acetyl 5-methoxytryptamine) on the growth rate of normal skin fibroblasts and of fibroblasts from involved and apparently uninvolved skin of patients affected by systemic sclerosis (SSc). METHODS: The growth rate was evaluated on the basis of growth curves and a 3H-thymidine incorporation assay. RESULTS: Our results demonstrate that a dose of 200 micrograms/ml of MLT inhibits (> 80%) both control and SSc fibroblasts. Inhibition was dose-dependent and was greater than 70% for MLT concentrations of 100 micrograms/ml, 200 micrograms/ml and 400 micrograms/ml. 3H-thymidine incorporation was correlated with the effect on the growth curves (81% at 200 micrograms/ml of MLT). In contrast, at a low dosage of 6 micrograms/ml, MLT exerted a stimulatory effect on cell proliferation in all the cell lines analyzed. Cell viability was not affected by MLT at any of the concentrations tested. A recovery study indicated that replacement of MLT-containing medium with MLT-free medium resulted in a re-establishment of cell growth. CONCLUSIONS: These results suggest that MLT, at higher dosages, is a potent inhibitor of the proliferation of fibroblasts derived from the skin of healthy and SSc patients.

Cell Count↗